FIG. 1 illustrates a plurality of host 10 (e.g., mainframes, a personal computers, or a workstations) connected to a storage subsystem 20, which in turn is connected to a storage subsystem 40, and connected to a storage subsystem 30, which in turn is connected to a storage subsystem 50 (e.g., storage systems may be automated media libraries). Each host 10 employs an operating system 11 (e.g., a IBM MVS operating system) and a storage manager 12 whereby operating system 11 initializes an initial operation mode of storage manager 12 in controlling I/O operations to a parallel access volume (“PAV”) of base logical volume(s) 21 and logical alias(es) 22 residing on storage subsystem 20, to a PAV of base logical volume(s) 31 and a logical alias(es) 32 residing on storage subsystem 30, to a PAV of a base logical volume(s) 41 and a logical alias(es) 42 residing on storage subsystem 40, and to a PAV of a base logical volume(s) 51 and a logical alias(es) 52 residing on storage subsystem 50.
Currently, a reconfiguration of each host 10 from an initial operation mode (e.g., a base PAV operation mode) to a new target operation mode (e.g., a HyperPAV operation mode) requires a re-IPLing of operating system 11 (e.g., a reloading of initial programs by operating system 11), which is impractical for a twenty-four (24) hours a day/seven (7) days a week/twelve (12) months a year host access of storage subsystems 20, 30, 40, 50. Thus, there is a need for a technique for reconfiguring host 10 to a new target operation mode exclusive of a re-IPLing of operating system 11.